Application of peroxymonosulfate and its activation methods for degradation of environmental organic pollutants: Review

A review of the recent advances on the treatment of industrial wastewaters by Sulfate Radical-based Advanced Oxidation Processes (SR-AOPs)

Peroxymonosulfate (HSO5– and PMS) is an optional bulk oxidant in advanced oxidation processes (AOPs) for treating wastewaters. Normally, PMS is activated by the input of energy or reducing agent to generate sulfate or hydroxyl radicals or both. This study shows that PMS without explicit activation undergoes direct reaction with a variety of compounds, including antibiotics, pharmaceuticals, phenolics, and commonly used singlet-oxygen (1O2) traps and quenchers, specifically furfuryl alcohol (FFA), azide, and histidine. Reaction time frames varied from minutes to a few hours at pH 9. With the use of a test compound with intermediate reactivity (FFA), electron paramagnetic resonance (EPR) and scavenging experiments ruled out sulfate and hydroxyl radicals. Although 1O2 was detected by EPR and is produced stoichiometrically through PMS self-decomposition, 1O2 plays only a minor role due to its efficient quenching by water, as confirmed by experiments manipulating the 1O2 formation rate (addition of H2O2) or li...

Oxidation of Organic Compounds in Water by Unactivated Peroxymonosulfate

In-situ chemical oxidation: Principle and applications of peroxide and persulfate treatments in wastewater systems

Efficient degradation of 2,4-dichlorophenoxyacetic acid by peroxymonosulfate/magnetic copper ferrite nanoparticles/ozone: A novel combination of advanced oxidation processes

Efficient integrated processes for pulp and paper wastewater treatment and phytotoxicity reduction: Permanganate, electro-Fenton and Co3O4/UV/peroxymonosulfate

Combined electrocoagulation and UV-based sulfate radical oxidation processes for treatment of pulp and paper wastewater

Chitosan (CS), synthesized from chitin chemically extracted from shrimp shells, was used for the synthesis of magnetic chitosan nanoparticles (Fe3O4-CSN), which makes the adsorbent easier to separate. Fe3O4-CSN was used for the removal of toxic metals such as vanadium (V(V)) and palladium (Pd(II)) ions from aqueous solutions. Influencing factors on the adsorption process such as pH, contact time, adsorbent dosage, and agitation speed were investigated. A competitive adsorption of V(V) and Pd(II) ions for the active sites was also studied. The monolayer maximum adsorption capacities (Qm) of 186.6 and 192.3 mg/g were obtained for V(V) and Pd(II) ions, respectively. The pseudo-second-order equation gave the best fit for the kinetic data, implying that chemisorption was the determining step. Freundlich model yielded a much better fit than the other adsorption models assessed (Langmuir, Temkin and Dubinin-Radushkevich). Thus, the adsorption of V(V) and Pd(II) ions onto Fe3O4-CSN is a combination of physical and chemical adsorption, as based on the kinetics and equilibrium study. Generally, physical adsorption is the mechanism that governs the system, while chemical adsorption is the slowest adsorption step that takes place. Thermodynamic studies displayed that the adsorption process was exothermic and spontaneous. Removal efficiencies of 99.9% for V(V) and 92.3% for Pd(II) ions were achieved, implying that Fe3O4-CSN adsorbent had an excellent ability for the removal of the metal ions from real industrial wastewaters without remarkable matrix effect.

Removal of vanadium and palladium ions by adsorption onto magnetic chitosan nanoparticles.

In this study, chitin was extracted from shrimp shells (SS) and characterized by scanning electron microscopy, X-ray diffraction, and Fourier transforms infrared spectroscopy. And investigate the adsorption of vanadium (V) and palladium (Pd) toxic metals onto the chitin. The effect of parameters such as the concentration of V and Pd, contact time, solution pH, adsorbent dose, cations, and anions were studied on the adsorption process. Kinetic, isotherm, and thermodynamic models were investigated. Genetic programming (GP) is used to obtain an appropriate equation showing the relationship between the variables. Experimental optimum conditions were found in the V and Pd concentrations of 25 mg/L, pH of 9, an adsorbent dose of 0.8 g/L and a contact time of 15 minutes. The maximum adsorption capacities (qm) of 13.15 and 12.65 mg/g were obtained for V and Pd, respectively. Among the anions and cations examined in this study, Ca2+ and SO42- had the greatest effect on the absorption of V and Pd on chitin. The adsorption kinetics followed a pseudo-second-order kinetic model and the equilibrium data showed a good fit of the Langmuir model and demonstrated a monolayer and favorable physisorption process. The thermodynamic analysis depicted that the process of adsorbing V and Pd using chitin was endothermic and spontaneous. Findings also presented GP as a potential tool for identifying the behavior of V and Pd adsorption. It can be concluded that chitin extracted from SS wastes, as a nontoxic and cheap adsorbent, could efficiently remove V and Pd from aqueous solutions. 

Maryam Omidinasab

Papers

Efficient integrated processes for pulp and paper wastewater treatment and phytotoxicity reduction: Permanganate, electro-Fenton and Co3O4/UV/peroxymonosulfate

Combined electrocoagulation and UV-based sulfate radical oxidation processes for treatment of pulp and paper wastewater

Removal of vanadium and palladium ions by adsorption onto magnetic chitosan nanoparticles.

Adsorptive of vanadium and palladium ions using chitin-extracted from shrimp shell wastes: genetic programming modeling